Centrifuge

ABSTRACT

A centrifuge has a drum which includes two axially adjacent substantially conical drum sections having respective end portions of widest diameter which are located adjacent one another and define a gap. A discharge control ring is sealingly interposed between the end portions and provided with apertures connecting the interior of the drum with the exterior thereof. A drive is provided for rotating the drum sections at a first speed, and for rotating the control ring at a different second speed, and closure elements are provided for selectively opening and closing the apertures to different extents.

United States Patent 1191 1111 3,843,044

Quetsch 1 Oct. 22, 1974 1 CENTRIFUGE 2,559,917 7/1951 Gresham 233/20 R Inventor: Johann Peter Qu BerghauSen 2,682,992 7/1954 Heckendorf 233/20 R Germany Primary Examiner-George H. Krizmanich [73] Assignee: Ernst Heinkel Maschinenbau KG, Attorney, Agent, or Firm-Michael S. Striker Karlsruhe, Germany 5 7] ABSTRACT A centrifuge has a drum which includes two axially adjacent substantially conical drum sections having respective end portions of widest diameter which are located adjacent one another and define a gap. A discharge control ring is sealingly interposed between the end portions and provided with apertures connecting the interior of the drum with the exterior thereof. A drive is provided for rotating the drum sections at a first speed, and for rotating the control ring at a different second speed, and closure elements are provided for selectively opening and closing the apertures to different extents.

14 Claims, 6 Drawing Figures PATENIEU 00122::124

cnurarruon BACKGROUND OF THE INVENTION The present invention relates generally to a centrifuge, and more particularly to a continuously operating centrifuge. Still more particularly, the present invention relates to a continuously operating centrifuge for separating solid particles from liquid in accordance with the sedimentation principle.

It is already known to provide so-called double-cone centrifuges and separators, that is devices having a drum shaped like a double cone whose narrowestdiameter ends are spaced axially apart from one another. The basic type of such device, wherein the drum is made of two halves or sections which are connected where they abut one another in their widest-diameter region, has the disadvantage that the solids can be discharged only intermittently by moving the drum sections axially apart, usually by hydraulic means. This means that the end of the solids discharge period cannot be accurately defined, and that therefore portions of the liquid can be discharged together with the solid. Also, insufficiently clarified liquid may be discharged in this type of apparatus.

Since the problem with this type of construction has been recognized before, an attempt has been made to overcome it by providing a double-conical drum wherein the two drum sections define with one another an annular gap. This gap is to be automatically adjusted during the operation of the centrifuge, and after separation of the solids and liquid from one another the solid material is to be continuously discharged through the gap, and the liquid is to be allowed to run off via adjustable outlet openings. This construction has the advantage that it is very simple and does not require costly hydraulic devices by contrast to the firstmentioned types of apparatus. However, in this type of device it is quite frequently difficult or even impossible to obtain proper separation of solids and liquids.

Still another prior-art construction proposes to discharge the solids via holes formed in the cylindrical outer jacket of the centrifuge drum. These holes are periodically opened and closed to thereby control the discharge of the solids. This construction has the disadvantage that while some of the solid material is readily discharged from the region of the openings, other of the solid material can settle on the drum wall intermediate these openings and is difficult to discharge. This renders the discharge nonuniform and creates the danger that an imbalance might develop in the drum which, of course, rotates at high speed during the separating operation.

SUMMARY OF THE INVENTION Accordingly, it is a general object of the invention to overcome the disadvantages of the prior art.

More particularly, it is an object of the present invention to provide an improved centrifuge construction wherein the solids can be discharged after the initial operation, in a continuous manner, and wherein a clear and effective separation between solid and liquid is obtained.

Another object is to provide such a centrifuge which permits the separation of liquid and solid according to the sedimentation principle.

An additional object of the invention is to provide such a centrifuge which is simple in its construction and operation, and requires neither inserts nor hydraulic devices.

In keeping withthe above objects, and with others which will become apparent hereafter, one feature of the invention resides in a continuously operating centrifuge for separating solids from liquids which, briefly stated, comprises a centrifuge drum including two axially adjacent substantially conical drum sections having respective end portions of widest diameter which are located adjacent one another. A discharge control ring is sealingly interposed between the end portions and provided with aperture means connecting the exterior of the drum with the interior thereof. 'Drive means is provided for rotating the drum sections of a first speed, and for rotating the control ring at a different second speed with reference to the drum sections. Closure means is provided for selectively opening and closing the aperture means to different extents.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a diagrammatic view of a centrifuge according to the present invention;

FIG. 2 is a fragmentary section through that part of the centrifuge which is identified with the brokenline circle A in FIG. ll;

FIG. 3 is a fragmentary plan view, in a developed view, showing a part of the periphery of the centrifuge drum and illustrating closing elements for the apertures in a first position;

FIG. 4 is a view similar to FIG. 3, illustrating the closure members in a different second position;

FIG. 5 is a view similar to FIG. 3, but illustrating a further embodiment of the invention; and

FIG. 6 is a view similar to FIG. 5, illustrating still another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail, and referring firstly to the embodiment illustrated in FIGS. 1-4, it will be seen that this is of a continuously operating centrifuge serving to separate solids from liquids in accordance with the sedimentation principle. The centrifuge has a rotatable drum 1 composed of two substantially conical drum sections lla, llb which diverge conically towards one another, so that their ends of widest diameter are located axially adjacent each other. They thus form a double-conical interior chamber 3 (see FIG. 2), at the periphery of which they are provided discharge openings 2 for the solid particles. Outlet openings 5 for the separated liquid are also provided, but being axially spaced from the region 4 where the interior 3 has its widest diameter. An opening 6 in the shaft 7 is provided for admission of the solid-liquid suspension into the centrifuge drum 1.

In this embodiment, a toothed belt drive 8 including belts 9, two belt pulleys l1 and 12, and a motor 13 serves to drive the two drum sections la and 1b in rotation. The belt pulley 11 transmits motion to a shaft 14 which drives the drum sections la and 1b.

A two-part control ring 15 is provided at the juncture between the widest-diameter end portions of the drum sections 1a and lb. The ring 15 is mounted on a carrier disk or plate 16 and is provided with at least one opening 2 which extends either substantially radially or at a slant, connecting the interior 3 of the drum 1 with the exterior thereof. If more than one opening 2 is provided, then these openings should be equi-angularly distributed about the circumference of the ring 15. The openings 2 are of enlarged cross section in the direction of discharge, that is outwardly of the drum. The purpose of providing the openings 2, if there is more than one, with an equi-angular spacing is to prevent any im-' balance from occurring in the drum 1.

It should be noted that the openings 2 are so formed in the control ring 15 that their boundary edges 17 are located on one side of the region 4, and the boundary edge portions 18 are located on the other side but slightly away from the region 4. The surfaces 21, 22, 23 and 24 of the drum sections 1a and lb, or the control ring portions 15a and 15b are located as closely as possible to the inlet 19 of the openings 2. These surfaces 21-24 enclose between themselves the caps 25 and 26 each of which extends at an inclination towards the region 4, so as to facilitate the sealing.

The sealing of the gaps is effected by sealing rings 27 and 28 which are retained by rings 20, 30, 31 and 32, these rings preferably having an angular cross section. The rings 29-32 are tension rings which are secured by bolts 33 to the drum sections In and lb, or else to the control rifig portions 150 and 15b.

Each of the openings 2 has an orifice 34 which in the illustratedembodiment in FIGS. l-4 may be closed by a pivotally mounted closing lever 35. Each of the levers 35 is provided with a cam-shaped raised portion or projection 36, and with a recess 37. When the levers 35 assume the position shown at the left-hand side of FIG. 3 and the right-hand side of FIG. 4, the portion 36 closes the respective orifice 34 of an associated discharge opening 2. Sealing plates 38 are recessed into the respective levers 35, and in the closure position of the levers 35 these sealing plates 38 sealingly overlie the respective orifices 34 to provide a good seal. The right-hand side of FIG. 3 and the left-hand side of FIG. 4 show the levers 35 to be in an opening position, that is in such a position that the orifice 34 of the respective discharge opening 2 is exposed, so that solid material may be discharged from the centrifuge drum 1.

In this embodiment, also, the drum section la is provided with stops 39, which are of course abutments and which project downwardly beyond the control ring 15. These stops or abutment 39 have a portion 40 which may engage a projection 41 of the respective closing lever 35. The projection 41, in turn, extends beyond the control ring 15 at the side adjacent to the stop 39 in certain pivotal positions of the closing lever 35, namely the positions shown in FIG. 3 on the left-hand side thereof. Due to this construction, a relative motion between the drum section la and the control ring 15 causes the projection 41 to be engaged by the portion 40 of an associated stop 39, and hence effects tilting of the closing lever 35 which, as pointed out earlier, is pivotally mounted.

In FIGS. 5 and 6 I have shown two other possibilities for closing the openings 2, to replace the closing levers 35. FIG. 5 shows that a toothed wheel with a plurality of projections may be utilized, so that the portions 40 of the stops 39 will repeatedly and intermittently engage the projecting cam portions 48 of the toothed wheel 47a. During such an engagement the orifice 34 of the associated opening 2 is exposed, and is subsequently closed again during the next engagement. In

the opening position each opening 2 registers with an opening 46a formed in the wheel 47a. FIG. 5 shows a position in which one of the openings 2 is exposed by being in registry with an opening 46a and the toothed wheel 7 47a, and FIG. 6 (which additionally shows a somewhat differently configurated toothed wheel 47b) shows this wheel 47b in a position in which the opening 2 is sealed because it is not in registry with any of the openings 46b formed in the wheel 47b. In all other respects, the wheel 47b'is the same as the wheel 47a and the operation is the same also. In FIG. 5 the arms or spokes of the wheel 47a are identified with reference numeral 48a, and in FIG. 6 they are identified with reference numeral 48b. 1

The movement of the stops 39 relative to the closing lever 35 in FIGS. 1-4, or the wheels 47a, 47b in FIGS. 5-6, is produced by so constructing the arrangement that the drum sections la or lb can execute a movement relative to the control ring 15. For this purpose the drum section la and the carrier plate 16 are driven at different rotational speeds. A further belt drive 42 is provided (see FIG. 1) for this purpose, having a slightly different transmission ratio from the belt drive 8.

Itwill be appreciated that if the drum sections la, lb and the carrier plate 16 are to be driven at identical speeds, the clutch 43 in FIG. 1 is engaged and the belt drive 8 drives the clutch 43, the plate 16 and hence the control ring 15 at the same speed of rotation by means of shaft 14, as the drum sections 1a, lb and the wedge 44. If, however, the drum sections 1a, lb are to be driven at one speed, and the plate 16 is to be driven at a different speed, then the clutch 43 is disengaged and a clutch 45 is engaged so that the belt 42 now drives the plate 16 at a different transmission ratio. It will be appreciated that the belt drive may be replaced by a correspondingly operating gear drive which can be switched to achieve the aforementioned transmissions.

A particular advantage of the novel centrifuge construction is the fact that it can be used for various different products, that is for separation of different liquid-solid suspensions. This is possible because the differential speed can be varied during discharge of the solids, and the opening and closing of the outlet openings 2 can be controlled at will. For instance, the closing levers 35 or the corresponding wheels may be set in one manner when perfectly sedimenting substances having a high solid content are to be separated, in which case all discharge openings 2 will constantly discharge solids. If, on the other hand, sedimentation properties are encountered which permit only a slow discharge of the separated solids, it is possible to allow only some of the openings 2 to be open. To provide for this possibility, some of the closing levers 35 are caused to assume the position shown in the right-hand side of FIG. 4 before centrifuging commences. The position of these closing levers does not alter when the stop 39 moves past the closing lever 35, so that the associated discharge opening 2 remains closed. Other closing levers, which at the beginning of the centrifuging operation were in the position shown in the left-hand side of FIG. 3, will be moved from the position onthe lefthand side of FIG. 3 to the position shown on the lefthand side of FIG. 4 by engagement with the respective stop 39 when the drum sections la, 1b and the carrier blade 16 are rotated at different speeds of rotation. The discharge of solids are effected constantly and evenly because the control ring 15, due to the difference in relative speed of the ring to the drum 1, will constantly carry the solid particles accumulated in the interior of the drum past the exposed discharge openings 2. This results in what might be termed a point of uniform pealing of of the solids. This occurs at the narrowest cross-section of the drum sections in, 1b, at the point of maximum centrifugal pressure upon the solid material which is accumulated on the wall of the drum sections.

To maintain the solid and liquid build-up in the drum interior, the quantity discharged may be varied over a wide range.

In addition to the aforementioned advantages, the

novel centrifuge construction is very simple in its structure and has only very few components which are subject to wear. This is particularly true with respect to the sealing rings 27 and 28 which are so located that, even when they do wear, they can be readily replaced by dismantling the rings 29-32, whereupon the sealing rings 27 and 28 can be removed and replaced with new ones.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a centrifuge, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way-from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. A continuously operating centrifuge for separating solids from liquids, comprising a centrifuge drum including two axially adjacent substantially conical drum sections havingrespective end portions of widest diameter which are located adjacent one another; a discharge control ring sealingly interposed between said end portions and provided with aperture means connecting the exterior of said drum with the interior thereof; drive means for rotating said drum sections at a first speed, and for rotating said control ring at a different second speed with reference to said drum sections; and closure means responsive to said first and second speeds for selectively opening and closing said aperture means to different extents.

2. A centrifuge as defined in claim 1, wherein said aperture means comprises a plurality of apertures which are equi-distantly spaced about said control ring.

3. A centrifuge as defined in claim 2, wherein said closure means comprises closure members which are turnably mounted on said control ring.

4. A centrifuge as defined in claim 3, said closure members being levers; and further comprising abutments provided on an outer side of one of said drum sections and positioned for engaging and turning said levers in response to relative angular displacement of said one drum section and said control ring.

5. A centrifuge as defined in claim 4, at least one of said levers having a projection extending beyond said control ring and adapted to engage one of said abutments.

6. A centrifuge as defined in claim 4, said levers having edge portions which are provided with arcuate recesses adapted to cooperate with respective associated apertures.

'7. A centrifuge as defined in claim 4, said levers having edge portions provided with a plurality of projections which cooperate with said abutments to effect intermittent turning of said levers, and with a corre sponding plurality of recesses adapted to cooperate with respective associated apertures.

8. A centrifuge as defined in claim 4; further comprising sealing members mounted on the respective levers and each adapted to overlie and seal one of said apertures when the associated lever is in an apertureclosing position.

9. A centrifuge as defined in claim 1, wherein said end portions of widest diameter surround a widestdiameter double-conical portion of the interior of said drum; and wherein said aperture means has one boundary edge portion located substantially on the widest diameter of said interior, and another boundary edge portion which is spaced from said widest diameter of said interior.

it). A centrifuge as defined in claim 1, said control ring defining respective annular gaps with said end portion of said drum sections; and further sealing rings for sealing said gaps; and retaining rings for retaining said sealing rings in sealing position.

11. A centrifuge as defined in claim 1, said control ring defining with said end portions of said drum sections respective annular gaps which are inclined in direction outwardly of said drum toward the widest diameter of the drum.

12. A centrifuge as defined in claim 1; and further comprising a mounting plate mounting said control ring and being rotatable independently of said drum section at rotational speeds equal to or different from those of said drum sections.

13. A centrifuge as defined in claim 12, said drive means comprising a drive motor, at least two belt drives, and coupling means for selectively connecting either or both of said belt drives with said drum sections and mounting plate.

14. A centrifuge asdefined in claim 12, wherein said drive means comprises a motor, and switchable gear drive means operatively connected with said motor,

drum sections and mounting plate. l l= l 

1. A continuously operating centrifuge for separating solids from liquids, comprising a centrifuge drum including two axially adjacent substantially conical drum sections having respective end portions of widest diameter which are located adjacent one another; a discharge control ring sealingly interposed between said end portions and provided with aperture means connecting the exterior of said drum with the interior thereof; drive means for rotating said drum sections at a first speed, and for rotating said control ring at a different second speed with reference to said drum sections; and closure means responsive to said first and second speeds for selectively opening and closing said aperture means to different extents.
 2. A centrifuge as defined in claim 1, wherein said aperture means comprises a plurality of apertures which are equi-distantly spaced about said control ring.
 3. A centrifuge as defined in claim 2, wherein said closure means comprises closure members which are turnably mounted on said control ring.
 4. A centrifuge as defined in claim 3, said closure members being levers; and further comprising abutments provided on an outer side of one of said drum sections and positioned for engaging and turning said levers in response to relative angular displacement of said one drum section and said control ring.
 5. A centrifuge as defined in claim 4, at least one of said levers having a projection extending beyond said control ring and adapted to engage one of said abutments.
 6. A centrifuge as defined in claim 4, said levers having edge portions which are provided with arcuate recesses adapted to cooperate with respective associated apertures.
 7. A centrifuge as defined in claim 4, said levers having edge portions provided with a plurality of projections which cooperate with said abutments to effect intermittent turning of said levers, and with a corresponding plurality of recesses adapted to cooperate with respective associated apertures.
 8. A centrifuge as defined in claim 4; further comprising sealing members mounted on the respective levers and each adapted to overlie and seal one of said apertures when the associated lever is in an aperture-closing position.
 9. A centrifuge as defined in claim 1, wherein said end portions of widest diameter surround a widest-diameter double-conical portion of the interior of said drum; and whErein said aperture means has one boundary edge portion located substantially on the widest diameter of said interior, and another boundary edge portion which is spaced from said widest diameter of said interior.
 10. A centrifuge as defined in claim 1, said control ring defining respective annular gaps with said end portion of said drum sections; and further sealing rings for sealing said gaps; and retaining rings for retaining said sealing rings in sealing position.
 11. A centrifuge as defined in claim 1, said control ring defining with said end portions of said drum sections respective annular gaps which are inclined in direction outwardly of said drum toward the widest diameter of the drum.
 12. A centrifuge as defined in claim 1; and further comprising a mounting plate mounting said control ring and being rotatable independently of said drum section at rotational speeds equal to or different from those of said drum sections.
 13. A centrifuge as defined in claim 12, said drive means comprising a drive motor, at least two belt drives, and coupling means for selectively connecting either or both of said belt drives with said drum sections and mounting plate.
 14. A centrifuge as defined in claim 12, wherein said drive means comprises a motor, and switchable gear drive means operatively connected with said motor, drum sections and mounting plate. 